wave_view_private.h

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/*
 * Copyright (C) 2017 Tim Mayberry <mojofunk@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#ifndef _WAVEVIEW_WAVE_VIEW_PRIVATE_H_
#define _WAVEVIEW_WAVE_VIEW_PRIVATE_H_
 
#include <deque>
 
#include "pbd/mutex.h"
#include "pbd/pthread_utils.h"
#include "waveview/wave_view.h"
 
namespace ARDOUR {
        class AudioRegion;
}
 
namespace ArdourWaveView {
 
struct WaveViewProperties
{
public: // ctors
        WaveViewProperties (std::shared_ptr<ARDOUR::AudioRegion> region);
 
        // WaveViewProperties (WaveViewProperties const& other) = default;
 
        // WaveViewProperties& operator=(WaveViewProperties const& other) = default;
 
public: // member variables
 
        samplepos_t            region_start;
        samplepos_t            region_end;
        uint16_t              channel;
        double                height;
        double                samples_per_pixel;
        double                amplitude;
        double                amplitude_above_axis;
        Gtkmm2ext::Color      fill_color;
        Gtkmm2ext::Color      outline_color;
        Gtkmm2ext::Color      zero_color;
        Gtkmm2ext::Color      clip_color;
        bool                  show_zero;
        bool                  logscaled;
        WaveView::Shape       shape;
        double                gradient_depth;
        double                start_shift;
 
private: // member variables
 
        samplepos_t            sample_start;
        samplepos_t            sample_end;
 
public: // methods
 
        bool is_valid () const
        {
                return (sample_end != 0 && samples_per_pixel != 0);
        }
 
        void set_width_samples (ARDOUR::samplecnt_t const width_samples)
        {
                assert (is_valid());
                assert (width_samples != 0);
                ARDOUR::samplecnt_t half_width = width_samples / 2;
                samplepos_t new_sample_start = std::max (region_start, get_center_sample () - half_width);
                samplepos_t new_sample_end = std::min (get_center_sample () + half_width, region_end);
                assert (new_sample_start <= new_sample_end);
                sample_start = new_sample_start;
                sample_end = new_sample_end;
        }
 
        uint64_t get_width_pixels () const
        {
                return (uint64_t)std::max (1LL, llrint (ceil (get_length_samples () / samples_per_pixel)));
        }
 
 
        void set_sample_offsets (samplepos_t const start, samplepos_t const end)
        {
                assert (start <= end);
 
                // sample_start and sample_end are bounded by the region limits.
                if (start < region_start) {
                        sample_start = region_start;
                } else if (start > region_end) {
                        sample_start = region_end;
                } else {
                        sample_start = start;
                }
 
                if (end > region_end) {
                        sample_end = region_end;
                } else if (end < region_start) {
                        sample_end = region_start;
                } else {
                        sample_end = end;
                }
 
                assert (sample_start <= sample_end);
        }
 
        samplepos_t get_sample_start () const
        {
                return sample_start;
        }
 
        samplepos_t get_sample_end () const
        {
                return sample_end;
        }
 
        void set_sample_positions_from_pixel_offsets (double start_pixel, double end_pixel)
        {
                assert (start_pixel <= end_pixel);
                samplepos_t new_sample_start = region_start + (start_pixel * samples_per_pixel);
                samplepos_t new_sample_end = region_start + (end_pixel * samples_per_pixel);
                set_sample_offsets (new_sample_start, new_sample_end);
        }
 
        ARDOUR::samplecnt_t get_length_samples () const
        {
                assert (sample_start <= sample_end);
                return sample_end - sample_start;
        }
 
        samplepos_t get_center_sample () const
        {
                return sample_start + (get_length_samples() / 2);
        }
 
        bool is_equivalent (WaveViewProperties const& other)
        {
                return (samples_per_pixel == other.samples_per_pixel &&
                        contains (other.sample_start, other.sample_end) && channel == other.channel &&
                        height == other.height && amplitude == other.amplitude &&
                        amplitude_above_axis == other.amplitude_above_axis && fill_color == other.fill_color &&
                        outline_color == other.outline_color && zero_color == other.zero_color &&
                        clip_color == other.clip_color && show_zero == other.show_zero &&
                        logscaled == other.logscaled && shape == other.shape &&
                        gradient_depth == other.gradient_depth);
                // region_start && start_shift??
        }
 
        bool contains (samplepos_t start, samplepos_t end)
        {
                return (sample_start <= start && end <= sample_end);
        }
};
 
struct WaveViewImage {
public: // ctors
        WaveViewImage (std::shared_ptr<const ARDOUR::AudioRegion> const& region_ptr,
                       WaveViewProperties const& properties);
 
        ~WaveViewImage ();
 
public: // member variables
        std::weak_ptr<const ARDOUR::AudioRegion> region;
        WaveViewProperties props;
        Cairo::RefPtr<Cairo::ImageSurface> cairo_image;
        uint64_t timestamp;
 
public: // methods
        bool finished() { return static_cast<bool>(cairo_image); }
 
        bool
        contains_image_with_properties (WaveViewProperties const& other_props)
        {
                return cairo_image && props.is_equivalent (other_props);
        }
 
        bool is_valid () {
                return props.is_valid ();
        }
 
        size_t size_in_bytes ()
        {
                // 4 = bytes per FORMAT_ARGB32 pixel
                return props.height * props.get_width_pixels() * 4;
        }
};
 
struct WaveViewDrawRequest
{
public:
        WaveViewDrawRequest ();
        ~WaveViewDrawRequest ();
 
        bool stopped() const { return (bool) _stop.load (); }
        void cancel() { _stop.store (1); }
        bool finished() { return image->finished(); }
 
        std::shared_ptr<WaveViewImage> image;
 
        bool is_valid () {
                return (image && image->is_valid());
        }
 
private:
        std::atomic<int> _stop; /* intended for atomic access */
};
 
class WaveViewCache;
 
class WaveViewCacheGroup
{
public:
        WaveViewCacheGroup (WaveViewCache& parent_cache);
 
        ~WaveViewCacheGroup ();
 
public:
 
        // @return image with matching properties or null
        std::shared_ptr<WaveViewImage> lookup_image (WaveViewProperties const&);
 
        void add_image (std::shared_ptr<WaveViewImage>);
 
        bool full () const { return _cached_images.size() > max_size(); }
 
        static uint32_t max_size () { return 16; }
 
        void clear_cache ();
 
private:
 
        WaveViewCache& _parent_cache;
 
        typedef std::list<std::shared_ptr<WaveViewImage> > ImageCache;
        ImageCache _cached_images;
};
 
class WaveViewCache
{
public:
        static WaveViewCache* get_instance ();
 
        uint64_t image_cache_threshold () const { return _image_cache_threshold; }
        void set_image_cache_threshold (uint64_t);
 
        void clear_cache ();
 
        std::shared_ptr<WaveViewCacheGroup> get_cache_group (std::shared_ptr<ARDOUR::AudioSource>);
 
        void reset_cache_group (std::shared_ptr<WaveViewCacheGroup>&);
 
private:
        WaveViewCache();
        ~WaveViewCache();
 
private:
        typedef std::map<std::shared_ptr<ARDOUR::AudioSource>, std::shared_ptr<WaveViewCacheGroup> >
            CacheGroups;
 
        CacheGroups cache_group_map;
 
        uint64_t image_cache_size;
        uint64_t _image_cache_threshold;
 
private:
        friend class WaveViewCacheGroup;
 
        void increase_size (uint64_t bytes);
        void decrease_size (uint64_t bytes);
 
        bool full () { return image_cache_size > _image_cache_threshold; }
};
 
class WaveViewDrawingThread
{
public:
        WaveViewDrawingThread ();
        ~WaveViewDrawingThread ();
 
private:
        void start ();
        void run ();
 
private:
        PBD::Thread* _thread;
};
 
class WaveViewThreads {
private:
        WaveViewThreads ();
        ~WaveViewThreads ();
 
public:
        static void initialize ();
        static void deinitialize ();
 
        static bool enabled () { return (instance); }
 
        static void enqueue_draw_request (std::shared_ptr<WaveViewDrawRequest>&);
 
private:
        friend class WaveViewDrawingThread;
 
        // will block until a request is available
        static std::shared_ptr<WaveViewDrawRequest> dequeue_draw_request ();
        static void thread_proc ();
 
        std::shared_ptr<WaveViewDrawRequest> _dequeue_draw_request ();
        void _enqueue_draw_request (std::shared_ptr<WaveViewDrawRequest>&);
        void _thread_proc ();
 
        void start_threads ();
        void stop_threads ();
 
private:
        static uint32_t init_count;
        static WaveViewThreads* instance;
 
        // TODO use std::unique_ptr when possible
        typedef std::vector<std::shared_ptr<WaveViewDrawingThread> > WaveViewThreadList;
 
        bool _quit;
        WaveViewThreadList _threads;
 
        mutable PBD::Mutex _queue_mutex;
        PBD::Cond          _cond;
 
        typedef std::deque<std::shared_ptr<WaveViewDrawRequest> > DrawRequestQueueType;
        DrawRequestQueueType _queue;
};
 
 
} /* namespace */
 
#endif